Landscape development at Lina myr fen, Eastern Gotland, 9000−2500 cal. yr BP

Abstract

Using diatoms, pollen, and geochemistry, we explore human habitation around Lina myr, Gotland, in relation to shore displacement. Archeological evidence has shown that Lina myr was an important area for its prehistoric human inhabitants. We investigate if and when Lina myr was connected to the sea and could therefore have been part of an inland water system useful for transport. A chronology was based on 14C AMS dating of terrestrial macrofossils and bulk sediments with dates ranging between 9100 and 2360 cal. yr BP. The initiation of the Littorina transgression was dated to 8500 cal. yr BP. A twofold pattern for the maximum sub-phase of the Littorina Sea is suggested from 8100 to 7500 cal. yr BP and from 6500 to 6000 cal. yr BP. The onset of cultivation and grazing was indicated by the presence of Hordeum and Plantago lanceolata in the pollen record during the Late Neolithic, at about 4580 cal. yr BP. During this time sea level was relatively higher than today and the Lina myr basin was connected with the Littorina Sea, which it continued to be until isostatic uplift caused it to become isolated at about 3820 cal. yr BP. After about 3000 cal. yr BP, human-made landscape changes intensified, grasslands increased, and shrublands decreased.

Holocene relative sea level changes in the Västervik‐Gamlebyviken region on the southeast coast of Sweden, southern Baltic Sea

“…The most recent study from the same isobase is from the eastern Gotland, 100 km east of V€ astervik, and indicates a complex history of shoreline displacement with marine transgressions reaching an altitude of 22 m a.s.l. during the Early to Middle Holocene (Strandberg et al 2020).…”

“…BOREAS (Karlsson & Hedenstr€ & Ris-Risberg 1998;om berg 1999Strandberg et al 2020). Brackishmarine species are species with a marine affinity, widespread in the Baltic Sea except from the northernmost part.…”

“…Lagoonal taxa (previously 'clypeus flora') are typical in shallow, low salinity bays. Halophilous taxa are salt-tolerant species whereas indifferent taxa can tolerate slightly saline water (Roe et al 2009;Strandberg et al 2020). In addition, diatoms were classified based on their habitat form, i.e.…”

“…For each cross-section, elevation values (in m a.s.l.) were extracted in GIS using a digital elevation model (based on LiDAR data with 0.1-m altitude resolution obtained from Lantm€ ateriet, the Swedish Mapping, Cadastral and Land Registration Authority; Strandberg et al 2020). In each of the cross-sections the lowest elevation value was determined, and the isolation threshold was selected from the highest of the selected (low) elevation values.…”

“…This pattern is similar to the Lina Myr curve from eastern Gotland located on the same isobase (2 mm a 1 ), 100 km to the east of V€ astervik with a threshold altitude of 9.5 m a.s.l. (Strandberg et al 2020). The relative sea level changes in our study area are further compared with the shore displacement curves from the Blekinge area, SE Sweden (Yu 2003;Berglund et al 2005) and the eastern Gulf of Finland in the eastern Baltic Sea (e.g.…”